1. Field of the Invention
The present invention relates to an image forming apparatus, such as a facsimile, a copier, a printer, etc., and a developer replenishing method.
2. Discussion of the Background Art
Conventionally, various image forming apparatuses employing two-component developer having toner and carrier have been proposed as described in Japanese Patent Application Laid Open No. 2003-57882. When developer is previously filled in a developer container included in a developing device and an image forming apparatus is shipped, the developer scatters from an opening of the developing device, from which a developing roller is partially exposed, because of vibration or inclination of the image forming apparatus during transportation. Further, the developer can possibly deteriorate due to contacting open air through the opening. Thus, a service person generally fills the developer in a vacant developer container when the image forming apparatus arrives at a user site.
Further, a carrier component included in two-component developer deteriorates when repeatedly used, so that a developing performance deteriorates. Thus, the developer including deteriorated carrier stored in the developing device is generally replaced with a new. To replace such developer, a service person calls on a user at a prescribed cycle, and collects old developer, and replenishes new developer in a vacant developer containing section.
To uniformly replenish developer over a short period of time to a new vacant developer containing section or a section emptied by collecting the developer, the inventor is developing an image forming apparatus as described below.
Specifically, when the developing device is attached to the image forming apparatus, a developer containing bottle containing developer is set to a developer inlet, and a conveyance screw for conveying the developer in the developer containing section is driven, so that the developer is replenished to the developer containing section.
To prevent duplicate replenishment of the developer, which is caused due to an error of a service person, a replenishment detection device detects if the developer containing section is vacant when the service person designates a developer replenishing operation via an operation panel or the like. If the replenishment detection device detects that the developer containing section is vacant, the developer is replenished.
When the developer stored in the developer containing bottle is entirely replenished to the developing device, the service person operates the operation panel and starts an initial setting operation, such as sensitivity correction operation for a tone density sensor, etc., so as to form an appropriate toner image.
However, developer in the developer containing bottle sometimes cannot be entirely replenished to the developer containing section because a power supply is sometimes turned off or developer sometimes clogs in the developer containing bottle during the developer replenishing operation. In such a situation, when the developer replenishment operation is attempted again, the developer replenishing operation cannot restarts, because some developer remains in the developer containing section.
Then, the inventor improved the image forming apparatus as follows. When a replenishment detection device detects if a developer containing section is vacant and the determination result is positive (i.e., the developer containing section is vacant), a replenishment permission flag for permitting a developer replenishing operation is raised, and the image forming apparatus is switched to a permission condition in which the image forming apparatus can execute the developer replenishing operation. When a developer replenishing operation is designated, it is detected if the replenishing permission flag is raised, and the developing replenishing operation is executed when the detection result is positive (i.e., the replenishment permission flag is raised). When developer in a developer containing bottle is entirely replenished to the developer containing section, a service person operates an operation panel and switches to a prohibition condition, in which a developer replenishment operation is prohibited, while lowering the replenishment permission flag. When the developer in the developer containing bottle is not entirely replenished to the developer containing section due to turning off of the power supply or clogging of the developer in the developer containing bottle during the developer replenishment operation, and accordingly the developer replenishing operation is executed again, the developer replenishment operation can be executed regardless if the developer containing section is vacant. Because, the replenishment permission flag is raised at the time.
However, a service person possibly forgets lowering the replenishment permission flag and replenishes new developer without collecting deteriorated developer remaining in the developer containing section, resulting in duplicative replenishment of developer.